fixed bug: #1633 Memory leak in M_Mathutils_Vector
The math types ( matrix, vector, quad ) now make
copies of data passed to them rather than holding
a pointer to memory that cannot be freed, or that
may go away unexpectedly.
This also clarifies the problem of who is responsible
for freeing memory allocations.
Pre-checkin files are tagged mem_leak-1 in case this
breaks something.
b711409f8d